Launch system for lighter-than-air-balloons

ABSTRACT

An example method for launching a high-altitude balloon includes securing a launch collar around a balloon envelope to form a choke point separating an upper portion of the balloon envelope from a lower portion of the balloon envelope. The balloon envelope is structurally secured to a launch platform via a tether that is coupled to the launch collar. The launch collar is configured such that release of the launch collar from the choke point releases the balloon envelope from the launch platform.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication No. 63/131,076, titled “Mobile Launch System and Methods forLighter-than-Air-Balloons”, and filed on Dec. 28, 2020, which is herebyincorporated by reference for all that it discloses or teaches.

BACKGROUND

High-altitude balloons can be a useful tool in a variety of applicationssuch as Earth observation, atmospheric sampling, celestial imaging, andcommunications repeating. Since high-altitude balloons are steered bywind, launch sites are often selected dynamically near the time oflaunch based on weather (wind direction and wind speed) as well as basedon the geographical area(s) of interest for a particular flyover.

The term “lighter than air balloon” refers to balloons filled with alift gas with a lower density than normal atmospheric gases so that theballoon rises as a result. Lighter-than-air balloons are typically verylarge (e.g., several meters in length) and extremely lightweight.Consequently, these balloons can be heavily affected by wind during thelaunch process.

Amplifying this problem is the fact that lighter-than-air balloons aretypically not completely filled at the time of launch. In these systems,the lift gas expands as the balloon rises, effectively filling theballoon envelope with increasing altitude. At the time of launch,lighter-than-air balloons may be ˜10% full of lift gas and notcompletely full until reaching a target altitude (e.g., 60,000 feet).When wind acts on a balloon envelope, the balloon fabric can take on theform of a spinnaker sailboat sail or a parachute that is vulnerable todisplacement and damage by large forces created by wind. Large lateralforces during a launch process can also create excessive lean in alighter-than-air balloon system. Excessive lean may cause the balloonsystem to swing like a pendulum during launch, risking a collisionbetween a payload and the ground.

In hot air balloon systems, it is common to anchor the balloon to theground using an extendable line during launch so that the balloon can belet out into the sky for some distance where the payload (e.g.,passenger-carrying basket) is a substantial height off the ground andunlikely to swing and hit the ground when the balloon is released. Withlighter-than-air balloons, however, this is not common because thesetypes of systems are so vulnerable to wind. Even a light wind may causean inflated part of the balloon to lean over excessively. In many cases,this lean is dramatic enough to exceed the force of free lift—meaning,the balloon is unable to rise regardless of how much line is let out.

Because wind presents such extreme challenges in launching high-altitudeballoons, existing solutions typically restrict launch to days with lowwinds.

SUMMARY

According to one implementation, a method for launching a high-altitudeballoon includes securing a launch collar around a balloon envelope toform a choke point separating an upper portion of the balloon envelopefrom a lower portion of the balloon envelope. The balloon envelope isstructurally secured to a launch platform via a tether that is coupledto the launch collar. The launch collar is configured such that releaseof the launch collar from the choke point releases the balloon envelopefrom the launch platform.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. These andvarious other features and advantages will be apparent from a reading ofthe following Detailed Description.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 illustrates an example system for launching a high altitudeballoon.

FIG. 2 illustrates a launch system configured for early operations of alaunch sequence.

FIG. 3 illustrates another launch system configured for additionaloperations of a launch sequence.

FIG. 4 illustrates another launch system configured for further exampleoperations of a launch sequence.

FIG. 5A illustrates a front-side view of example launch collar suitablefor assisting in launch of a high-altitude balloon in any of the launchsystems shown in FIG. 1-4 .

FIG. 5B illustrates a back-side view of the example launch collar ofFIG. 5A.

FIG. 5C illustrates the example launch collar of FIGS. 5A and 5B with areleasable ring-lock mechanism shown in a locked state.

FIG. 6 illustrates a launch system similar to that shown in FIG. 1-4 ,but that further includes a self-orienting aerodynamic device that helpsto stabilize a balloon envelope to protect a payload during launch.

FIG. 7 illustrates example operations for launching a balloon system inhigh winds.

DETAILED DESCRIPTION

A mobile launch system disclosed herein includes features that enablelaunch of a lighter-than-air balloon in high winds. Due to mobility ofthe launch system, the launch can occur from any location—even locationsdifficult to access or that would traditionally be unavailable due tocharacteristically unfavorable weather (wind). This ensures that launchcan occur from a precise location on the ground that is selected toensure the balloon's trajectory flies over a preselected point on theground.

According to one implementation, a mobile launch system includes aunique launch collar that also acts as an anchor for the balloonenvelope while the balloon envelope is being filled with a lift gas. Thelaunch collar forms a choke point around the balloon envelope, dividingupper and lower portions of the balloon envelope from one another. Thelaunch collar is structurally secured to an earth-based anchor-pointwhile the upper portion of the balloon is being filled with a lift gas.Structurally securing the balloon further “up” the balloon envelope inthis manner effectively reduces total system “lean” for any given wind.That is due, in part, to the fact that the length of fabric that istorqued by wind is shortened, which changes the center of pressure fromlateral wind force. The reduction in lean is also partially attributableto a change in the center of lift for the system that is caused byinjecting lift gas into the balloon through a fill port that ispositioned above the launch collar—a location that is higher up on theballoon envelope than in traditional systems.

Reducing the effective lean of the balloon system in high winds reducesthe likelihood that the balloon will swing like a pendulum upon releaseand potentially crash the payload into the ground. Additionally, thereduction of this lean facilitates launch of the balloon system in veryhigh winds that would—in other systems—prevent launch by causing theballoon fabric to fan out like a sail and create a large torque thatcounteracts the lift force.

In the above-described implementation, balloon envelope fabric below thelaunch collar (e.g., below the choke point) is permitted to pivot aboutthe earth-based anchor point and may be blown upwards by lateral winds.The upward force counters the downward force created by pivoting of theupper portion of the balloon envelope above the pivot point, furtherstabilizing the balloon and reducing wobble when the balloon isreleased.

According to yet another implementation, a launch method disclosedherein provides for controlled release of a balloon system by decouplinga tether from an attachment point on a launch collar that is wrappedaround the balloon envelope to form a choke point. When released, theballoon contains lift gas in an upper portion above the choke point. Thelift force of the balloon causes the tether to decouple from the launchcollar, and the mechanics of the launch collar are such that it is notpossible for the balloon to rise away from earth with the launch collarstill attached. This ensures the balloon will not explode due toexpanding lift gas trapped in the balloon envelope above a choke pointcreated by the launch collar.

In still another implementation, the launch collar is wrapped around theballoon envelope and secured to a top of a mast on a ground-basedplatform while the upper portion of the balloon above the launch collaris injected with lift gas. The distance between the top of the mast andthe ground may exceed a distance between the launch collar and a payloadattached to the balloon envelope, ensuring that the payload cannotcollide with the ground even under extreme winds.

These and other advantages are explored in detail below with respect tothe following figures.

FIG. 1 illustrates a system 100 for launching a high-altitude balloon103 in high winds. The high-altitude balloon 103 may, in differentimplementations, include a variety of different features but is in atleast one implementation a lighter-than-air balloon. The high-altitudeballoon 103 includes a payload 104 and a balloon envelope that includesan upper portion 108 and a lower portion 110. Launch of thehigh-altitude balloon 103 is assisted by a launch collar 106, shownwrapped around a central portion of the balloon envelope 102 to form achoke point in the fabric of the balloon envelope 102. The choke pointformed by the launch collar 106 separates the upper portion 108 from thelower portion 110 of the balloon envelope 102. In FIG. 1 , the balloonenvelope 102 is shown with a lift gas in it just before a controlledlaunch sequence. The lower portion 110 of the balloon envelope 102 isunfilled and appears as a long tail of fabric that hangs from the chokepoint formed by the launch collar 106.

Although not shown in detail in FIG. 1 , the high-altitude balloon 103is structurally secured by the launch collar 106 to a tether 114 that isfurther affixed to a mast 112 on a ground-based platform 120. As usedherein, “ground-based platform” is used to imply a platform that is onthe ground or on a vehicle on the ground. In FIG. 1 , the ground-basedplatform 120 is shown to be part of an automobile (e.g., a truck 130).This is advantageous, as it may allow for launch of the high-attitudeballoon 103 from a variety of select and/or hard-to reach locations tofacilitate precise placement of the balloon system along a pre-selectedflight path. In other implementations, the ground-based platform 120 isa semi-permanent or permanent (non-mobile) platform. For example, theground-based platform may be a stage built upon or including theunderlying ground.

The tether 114 is coupled to one or more attachment points on the launchcollar 106. Exemplary features of the launch collar 106 are shown inmagnified view 118 and discussed further with respect to other featuresshown herein. In one implementation, the launch collar 106 includes apiece of fabric that is rolled around the balloon envelope and that issecured by a strap including one or more coupling mechanisms (rings) ateither end. The tether 114 engages with the launch collar 106 andtensions the launch collar 106 against the underlying fabric.

In one implementation, the tether 114 is threaded through the couplingmechanism on the launch collar 106 and has first and second ends thatare distal from the collar and secured, prior to launch, at respectiveattachment points on or near the ground-based platform 120. Duringlaunch, one of the ends of the tether 114 is released. This end isreferred to herein as the “release end” while the other opposite end ofthe tether is referred to as the “anchor end.” The anchor end is, in oneimplementation, securely anchored to the mast 112. The release end ofthe tether 114 opposite the anchor end is, prior to launch, also securedto the mast 112 or to another ground-based attachment point. As usedherein, the term ground-based attachment point refers to any point thatis substantially fixed relative to Earth and/or to the ground-basedplatform 120. For example, a ground-based attachment point may be apoint on the ground-based platform 120, the ground external to theground-based platform 120, or even in the hands of a person (e.g., anoperator) standing on or near the ground-based platform 120.

While the high altitude balloon 103 is secured to the ground-basedplatform 120, the upper portion 108 of the balloon envelope 102 containsa lift gas, such as helium, hydrogen, or any other lift gas. Notably, afill port 132 is located in the upper portion 108 just above the launchcollar 106. Tubing 122 facilitates the flow of gas from tank(s) 124 onthe ground-based platform 120 into the upper portion 108 of the balloonenvelope 102. The flow of lift gas may be controllably metered by anoperator interacting with controls on a control panel 126 or othersuitable automatic or manual control means.

According to one implementation, the high altitude balloon 103 isreleased and allowed to rise (launch) when the upper portion 108 of theballoon envelope contains a lift gas. For example, the upper portion 108of the balloon envelope 102 may be just 10% filled with lift gas at thepoint in time when a controlled release is initiated. The lift gasexpands as it rises; thus, the balloon envelope 102 continues togradually self-fill as the high-altitude balloon 103 rises to altitude.

Although launch collars are used in some existing balloon systems tohelp control the balloon envelope while it is being filled, thesetraditional launch collars function differently in both design andpurpose from those disclosed herein. In these existing systems, a linebetween the launch collar and launch platform does not serve as aprimary structural securement line that is paid out (controllablyreleased to allow the balloon to rise) during launch. Rather, the collaris typically released by a manual act just after release of a mainstructural securement line. In these systems, malfunction of the launchcollar (e.g., failed release) can lead to scenarios where the balloonlaunches while the launch collar is still attached. Due to the expandinglift gas and fixed size of the balloon envelope above the launch collar,the balloon inevitably explodes at some point during ascension.

In the disclosed system, however, it is the release of the launch collar106 that facilitates the controlled release of the high-altitude balloon103. That is, the balloon cannot be freed of its anchor to theground-based platform 120 unless and until the launch collar 106 isreleased. Mechanisms for controlled release of the launch collar 106 arediscussed with respect to other features herein.

FIG. 2 illustrates a launch system 200 configured for early operationsof a launch sequence. The system of FIG. 2 includes many of the featuresof FIG. 1 including the high-altitude balloon 203 and launch platform220 which is, by example and without limitation, shown integrated intothe back of a vehicle 230. The launch platform 220 includes a mast 212that serves as an anchor point for a tether 214 attached to a launchcollar 216 that is wrapped around a central portion of a balloonenvelope 202 to form a choke point separating an upper portion 208 ofthe balloon envelope 202 from a lower portion of the balloon envelope102.

In one implementation, the tether 214 has two opposite ends that areboth secured to attachment points on the launch platform 220 or otherground-based attachment points prior to launch. A first end (the anchorend) of the tether 214 is fixedly secured to a mast 212 while a secondend (the release end) is temporarily secured to the mast 212 or otherground-based attachment point. For example, the release end of thetether 214 may include a spool of additional line that is secured priorto launch and the controllably released (paid out) by an operator orautomated mechanism during launch of the high altitude balloon 203. Acentral portion of the tether 214 is coupled to the launch collar 206.As shown in greater detail in magnified view 218, the tether 214 may bethreaded through one or more apertures (e.g., rings) on the launchcollar 206.

In FIG. 2 , the upper portion of the balloon envelope 208 contains alift gas as discussed above with respect to FIG. 1 . The lift gascreates a lift force that pulls upward on the tether 214. During acontrolled launch operation, additional line of the tether 214 is slowlypaid out (e.g., from a spool) while the opposite end of the tetherremains anchored to the mast 212. The lift force on the balloon envelope202 against the newly-released line causes the coupling mechanisms(e.g., rings) on the launch collar 206 to pull away from the anchoredend of the tether 214 and slide along the tether 214 such that the liftforce slowly lifts the launch collar 206 away from the mast 212.

In a launch operation illustrated in FIG. 2 , some of the release linehas been paid out (e.g., gradually released from a spool or otherattachment point) to allow the upper portion 208 of the balloon envelope202 to rise a short distance above the launch platform 220. Due to this,the effective length of the tether 214 between the launch collar 206 andmast 212 is longer in FIG. 2 than in FIG. 1 . In this view, it is easierto see that the high-altitude balloon 103 is structurally secured by thelaunch collar 206 up until the moment of launch. In one implementation,the high-altitude balloon 103 is structurally secured by the launchcollar 206 (as shown) and not secured by any other line or attachmentmechanism during the launch operations up until the balloon is released.

According to one implementation, the launch collar 206 includes aring-lock mechanism that remains in a locked state against the fabric ofthe balloon envelope 202 as long is the rings (e.g., rings shown inmagnified view 218) remain under tension with the tether 214 threadedthrough the rings.

When the upper potion 208 of the balloon envelope 202 has risen a safedistance from the launch platform 220 (e.g., far enough to mitigate riskof a payload 204 colliding with the ground upon release), an operator orautomated process may completely let go of the release end of the tether214. The lift force acting on the balloon envelope 202 pulls the launchcollar 206 upward, causing the rings to slide relative to the tether 214while the anchored end of the tether 214 remains fixed to the launchplatform 220. Eventually, the released end of the tether 214 slides outof the launch collar 206, which in turn causes the launch collar 206 toopen and fall away from the balloon envelope 202, freeing thehigh-altitude balloon 203 to rise into the atmosphere. Thus, it is theseparation of the tether 214 from the launch collar 206 thatstructurally releases the high-altitude balloon 203 from the launchplatform 220. As explained above, this configuration prevents scenarioswhere the high-altitude balloon system 203 is inadvertently releasedwith the launch collar 206 still attached, leading to explosion of theballoon envelope 202 and a potentially dangerous crash of the payload204 back to earth.

In addition to protecting the balloon from explosions in scenarios wherethe launch collar does not release during launch, structurally securingthe balloon further “up” the balloon envelope 202 as shown (e.g., at theillustrated location of the launch collar 206 rather than at the bottomnear the payload 204) effectively reduces total lean of the balloonenvelope 202 for any given wind. In systems that structurally secureballoons at or near the payload 204, there exists a much longer lengthof fabric that is vulnerable to being torqued by wind than in theillustrated system 200 due to the fact that the full length of theballoon envelope is permitted to pivot along a single torque axisrelative to structural securement (pivot) point. Locating the structuralsecurement (pivot) point higher up on the balloon envelope 202, such asat the illustrated location of the launch collar 206, reduces the lengthof fabric relative to the corresponding pivot point in the presence ofwind, which in turn reduces the magnitude of the torque acting on thefabric. Instead of one long torque pulling the balloon envelope, thereare effectively two separate smaller torques that act in differentdirections relative to the pivot point at the launch collar 206. Thisreduces total lean of the high-altitude balloon system 203 during launchwhen winds are present.

Additionally, since the illustrated configuration permits wind to blowthe lower portion 210 of the balloon envelope 202 upwards toward thelaunch collar 206, an upward force is created to counter the downwardforce created by pivoting of the upper portion 208 of the balloonenvelope 202 above the launch collar 206. This further stabilizes theballoon and reduces wobble when the balloon is released, which reducesthe likelihood of the payload 204 striking the ground in the momentsleading up to lift-off.

In different implementations, the launch collar 206 may be attached atdifferent points along the length of the balloon envelope 202. In oneimplementation, the launch collar 206 is attached to the balloonenvelope at a location relative to a top end of the balloon envelopecorresponding to about ⅓ of the total fabric length top-to-bottom. Inother implementations, the launch collar 206 may be attached closer to amidpoint of the balloon envelope.

Features of FIG. 2 not specifically described above may be assumed to bethe same or similar to like-named components discussed elsewhere herein.

FIG. 3 illustrates another launch system 300 configured for additionalexample operations of a launch sequence. The launch system 300 has manyof the same components as FIG. 2 that serve the same functions as thosedescribed above.

Prior to launch, a high-altitude balloon system 303 is configured with alaunch collar 306 wrapped around a central portion of a balloon envelope302, forming a choke point that separates an upper portion 308 of theballoon envelope 302 from a lower portion 310 of the balloon envelope302. During launch, a tether 314 structurally secures the launch collar306 (and thereby, the high-altitude balloon system 303) to a mast 312 ona launch platform 320. Initially, the tether 314 is secured with a shortleash such that the launch collar 306 is in close proximity to thelaunch platform 320. For example, the launch collar 306 may be touchingor a few inches away from the mast 312, as illustrated FIG. 1 . Thetether has two opposite ends secured to or near the launch platform 320and a central portion threaded through rings on the ring-lock mechanism330 of the launch collar 306. During a launch sequence, a first end ofthe tether 314 (a “release end 328”) is gradually paid out from a spoolor other structure and finally released entirely from its associatedground-based attachment point.

In one implementation, the mast 312 has a height such that a distancebetween the top of the mast 312 and the ground exceeds a distancebetween the launch collar 306 and a payload 204 attached to the lowerportion of the balloon envelope 302. This configuration ensures that thepayload 304 cannot collide with the ground while the release end 328 isbeing paid out, as shown in FIGS. 2 and 3 .

The ring-lock mechanism 330 remains in a locked state as long as thetether 314 remains threaded through the rings (e.g., as shown inmagnified view 318). Features of FIG. 3 not specifically described abovemay be assumed to be the same or similar to like-named componentsdiscussed elsewhere herein.

FIG. 4 illustrates another launch system 400 configured for furtherexample operations of a launch sequence for a high-altitude balloon 403.Features of the launch system 400 are the same or similar to thosedescribed above with respect to any of FIG. 1 -FIG. 3 . Prior to launch,a launch collar 406 is secured around a balloon envelope 402, creating achoke point between upper and lower portions of the balloon envelope402. The launch collar 406 is secured to a mast 412 via a tether 414.When a first end of the tether is released, as shown in FIG. 3 (e.g.,with an opposite end still anchored to a launch platform 420 or otherground-based attachment point), the lift force on the balloon envelope402 causes the tether 414 to slide relative to a ring-lock mechanism(not shown) on the launch collar 406 such that the launch collar 406 uptoward released end of the tether 414. Eventually, the tether 414unthreads itself from the launch collar 406, immediately releasingtension in the ring-lock mechanism, which allows the launch collar 406to fall open and separate from the balloon envelope 402 as shown in FIG.4 . The launch collar 406 falls down to the ground and the balloonascends, gradually inflating with altitude due to expansion of the liftgas.

At this point, the high-altitude balloon system 403 is free to rise intothe atmosphere. There is no risk of the launch collar 406 failing toseparate from the balloon because the separation of the launch collar406 from the balloon envelope 404 is the mechanism that releases thehigh-altitude balloon system 403.

FIG. 5A illustrates a front-side view of example launch collar 500suitable for assisting in launch of a high-altitude balloon in any ofthe launch systems shown in FIG. 1-4 . The illustrated side of thecollar is, in one implementation, the side that faces outward (away fromthe balloon envelope) when in use. The launch collar 500 includes a mainportion 508 and a releasable ring-lock mechanism 502. Although otherlocking mechanisms may be suitable, the releasable ring-lock mechanism502 include includes a strap 504 with a middle portion 506 attached to(e.g., stitched) to the main portion 508 of the launch collar 500. Afirst end of the strap 504 is coupled to first ring 510, while a secondend of the strap is coupled to second and third rings 512 and 514, asshown.

FIG. 5B illustrates a back-side view of the example launch collar 500 ofFIG. 5A. The side shown in FIG. 5B is the side of the launch collar 500that faces toward the balloon envelope when in use. From this view, thesecond and third rings 512 and 514 are visible on the strap 504, but thefirst ring 510 is not.

FIG. 5C illustrates the example launch collar 500 of FIGS. 5A and 5Bwith the releasable ring-lock mechanism 502 shown in a locked state. Inthis view, it can be seen that the ring 512 is bigger than the ring 510and that the ring 510 is bigger than the ring 514. For this reason, thefollowing description refers to ring 512 as the “large ring 512”, thering 510 as the “medium ring 510”, and the ring 514 as the “small ring514.”

To place the launch collar 500 in the locked state shown in FIG. 5C, themain portion 508 is rolled such that the front side (view shown in FIG.5A) faces outward. Ends of the strap 504 are pulled around the rolledmain portion 508 and toward one another, as shown. A tether 518 isthreaded through the rings. In the illustrated implementation, thetether 518 is looped around the medium ring 510 by pulling a first end516 (e.g., a release end) of the tether 518 under, up, and through themedium ring 510, as shown. Then, the first end 516 is then sequentiallythreaded through the small ring 514 and the large ring 512.

In one implementation where the launch collar 500 is implemented in thesystem shown in FIG. 3 , the above-described threading of the first end516 of the tether 518 is performed while a second opposite end (“theanchor end”) remains secured to a ground-based attachment point. Afterbeing threaded through the rings of the releasable ring-lock mechanism502, the first end 516 is also secured to a ground-based attachmentpoint (e.g., tied to a fixed point or held in an operator's hands). Aslong as both ends of the tether 518 are secured to ground-basedattachment points, the releasable ring-lock mechanism 502 remains undertension and the rings cannot open.

During a controlled launch sequence, the first end 516 of the tether maybe gradually paid out, easing tension in the line to allow the launchcollar 500 to slide along the tether 518 in the direction of the firstend 516. When the first end 516 is completely set free, the tether 518first decouples from the large ring 512, then the small ring 514 andfinally, the medium ring 510. This releases remaining tension in thereleasable ring-lock mechanism 502, allowing the main portion 508 of thelaunch collar 500 to unroll and fall away from the balloon envelope.

According to one implementation, the relative sizes of the rings aresuch that the small ring 514 can fit through the large ring 512 but notthrough the medium ring 510. This is sufficient to enable locking actionwhile also ensuring that sudden quick tension in the tether 518 does ininadvertently suck the small ring 514 through the medium ring 510, whichcould jam the release mechanism. Additionally, use of three rings in thereleasable ring-lock mechanism 502 rather than two is beneficial becauseit reduces rubbing on the balloon envelope in the transition period whenthe launch collar 500 is first beginning to open, thereby reducing arisk of damage to the balloon envelope at this moment in time.

FIG. 6 illustrates a launch system 600 similar to that shown in FIG. 1-4, but that further includes a self-orienting aerodynamic device 616 thathelps to stabilize a balloon envelope 602 to protect a payload 604during launch. In FIG. 6 , the self-orienting aerodynamic device 616 isshown to be a kite but may assume other forms in other implementationssuch as that of a wing-shaped parachute (parafoil), or any otheraerodynamic device that creates lift when presented with a cross-wind.

To demonstrate the benefits of the disclosed launch process as well asthe utility of the self-orienting aerodynamic device 616, FIG. 6 furtherillustrates various forces at play during launch of a high-altitudeballoon system 603. The high-altitude balloon system 603 includes aballoon envelope 602 anchored via a launch collar 606, as generallyshown and described with respect to FIG. 1-4 .

A buoyancy force 612 and drag force 614 caused by wind 618 create atension force that may have a downward component (towards the earth) dueto a tether 632 anchoring the balloon system to the ground (e.g., to apoint below the wind 618). The wind 618 causes the balloon to lean over,and a downward force 622 is caused by the weight of a payload 604 andmaterial of the balloon envelope 602. If the sum of the downward forcesdescribed exceed the buoyancy force 612 pulling up on a balloon envelope602, the balloon may not rise into the sky if let out. However,anchoring the balloon envelope 602 by the launch collar 606 instead of alower point on the balloon allows a lower portion (balloon stalk) of theballoon envelope 602 to be potentially pushed up, as shown by upwardaerodynamic lift force 624 that counteracts the downward forces,assisting in lift.

Additionally, this configuration where the lower portion (balloon stalk)blows upward in the wind can help to prevent pendulum swing that occursin systems that anchor the balloon envelope 602 is anchored at a lowerpoint, such as at the payload 604. In the illustrated configuration, theupper portion of the balloon envelope 602 is pushed into a lean by thedrag force 614 while the lower portion of the balloon envelope 602 ispushed over by the drag force 614 and up by the aerodynamic lift force624. When released, the payload 604 may swing toward an anchor point 628while the upper portion of the balloon envelope 602 continues to move upand away from the anchor point 628, perhaps leaning somewhat in thedirection of the drag force 614. Since these forces counter-act oneanother, there is very little pendulum swing. Any pendulum swing thatdoes occur is counteracted by the opposing motion in upper and lowerportions of the balloon envelope, ensuring that the payload 604 does notget close the ground when the balloon is released.

For high wind situations, the self-orienting aerodynamic device 616(e.g., a delta wing kite or parafoil) may be optionally utilized tocreate an additional upward force 630 helping to counteract system leanand get a balloon system higher into the sky for release. In FIG. 6 ,the self-orienting aerodynamic device 616 is shown attached to thelaunch collar 606. When the launch collar 606 is released from theballoon (as described elsewhere herein), the self-orienting aerodynamicdevice 616 remains attached to the launch collar 606 and thus would notcontinue to fly with the balloon system.

FIG. 7 illustrates example operations 700 for launching a balloon systemin high winds. A securing operation 702 secures a launch collar around aballoon envelope to form a choke point that separates an upper portionof the balloon envelope from a lower portion of the balloon envelope.Another securing operation 704 structurally secures the balloon envelopeto a mobile launch platform (e.g., an automobile) with a tether thatextends between the launch collar and one or more ground-basedattachment points either on or next to the mobile launch platform.According to one implementation, opposite ends of the tether are securedto the ground while a middle portion of the tether is coupled to alocking mechanism on the launch collar.

In one implementation, one or both ends of the tether are secured to atop end of a mast on the launch platform. A distance between the mastand the ground exceeds a distance between the launch collar and apayload of the balloon system. This configuration ensures the payloaddoes not strike the ground at the moment when the balloon system isreleased from the tether. A filling operation 706 puts a lift gas intothe upper portion of the balloon envelope with a lift gas while theballoon envelope is structurally secured to the launch platform by thetether and the launch collar.

While the balloon envelope is rising under a lift force generated by thelift gas, a releasing operation 708 releases the launch collar from theballoon envelope thereby releasing the balloon system into the sky.According to one implementation, the launch collar is released from theballoon envelope when a first end of the tether is set free of acorresponding one of the ground-based attachment points while anopposite second end of the tether remains under tension and attached toanother one of the ground-based attachment points.

The above specification, examples, and data provide a completedescription of the structure and use of exemplary embodiments of thedisclosed technology. Since many embodiments of the disclosed technologycan be made without departing from the spirit and scope of the disclosedtechnology, the disclosed technology resides in the claims hereinafterappended. Furthermore, structural features of the different embodimentsmay be combined in yet another embodiment without departing from therecited claims.

What is claimed is:
 1. A method of launching a high altitude ballooncomprising: securing a launch collar around a balloon envelope to form achoke point separating an upper portion of the balloon envelope from alower portion of the balloon envelope; structurally securing the balloonenvelope to a launch platform via a tether coupled to one or moreattachment points on the launch collar, the tether also being secured atone or both ends to one or more ground-based attachment points; andinjecting lift gas into the upper portion of the balloon envelope whilethe balloon envelope is structurally secured by the tether and thelaunch collar; and controllably releasing a first end of the tether froma corresponding one of the ground-based attachment points while theballoon envelope is rising under a lift force generated by the lift gas,the lift force generating an upward tension that disengages the tetherfrom the launch collar by pulling the released first end of the tetherback through one or more apertures on the launch collar, wherein releaseof the launch collar from the choke point releases the balloon envelopefrom the launch platform.
 2. The method of claim 1, the disengagement ofthe tether from the launch collar causes the launch collar to open andfall away from the choke point on the balloon envelope.
 3. The method ofclaim 1, wherein the launch collar includes a ring-lock mechanismincluding a central portion that wraps around the choke point and astrap that secures the central portion in place when wrapped around thechoke point, the strap including at least one ring at each end, thetether being threaded through the at least one ring at each end of thestrap when the launch collar is in a locked state.
 4. The method ofclaim 3, wherein the strap on the ring-lock mechanism includes a smallring, a medium ring, and a large ring, and wherein the small ring restsbetween the medium ring and the large ring when the ring-lock mechanismis in a locked state.
 5. The method of claim 4, wherein the small ringcan fit though the large ring but not through the medium ring.
 6. Themethod of claim 3, wherein the ring-lock mechanism is configured to:apply tension to place the launch collar in a locked state around thechoke point when the tether is under tension between the launch collarand the ground-based attachment points; and release the tension when thetether is decoupled from the at least one ring at each end of the strap,the release of the tension causing the launch collar to fall away fromthe balloon envelope.
 7. The method of claim 1, further comprising:attaching the launch collar to a top of a mast on the launch platformbefore filling the balloon envelope with the lift gas, wherein adistance between the top of the mast and underlying ground exceeds adistance between the launch collar and a payload attached to the lowerportion of the balloon envelope.
 8. The method of claim 1, furthercomprising: anchoring a self-orienting aerodynamic device to the launchcollar, the self-orienting aerodynamic device configured to generate alift force when a cross-wind is present.
 9. The method of claim 1,wherein the launch platform is an automobile.
 10. The method of claim 1,wherein a fill port is located in the upper portion of the balloonenvelope at a location above the launch collar.
 11. A launch systemcomprising: a balloon system including a balloon envelope and a payload;a launch collar with a locking mechanism, the launch collar beingconfigured to wrap around the balloon envelope to form a choke pointseparating an upper portion of the balloon envelope from a lower portionof the balloon envelope, the upper portion of the balloon envelopecontaining a lift gas; a tether threaded through one or more aperturesof the locking mechanism on the launch collar, the tether and the launchcollar functioning to structurally secure the balloon envelope to alaunch platform, wherein the tether is configured to disengage from theone or more apertures of the launch collar in response to a controlledrelease of a first end of the tether while the balloon envelope isrising under a lift force generated by the lift gas, and wherein releaseof the launch collar from the choke point releases the balloon envelopefrom the launch platform.
 12. The launch system of claim 11, wherein thelocking mechanism includes two or more apertures coupled with thetether, the launch collar being configured to open and fall away fromthe choke point on the balloon envelope when the tether decouples fromthe two or more apertures.
 13. The launch system of claim 11, whereinthe locking mechanism is a ring-lock mechanism that includes a strapthat wraps around the launch collar, the strap including at least onering at either end, the tether being threaded through the at least onering at each end of the strap when the locking mechanism is in a lockedstate.
 14. The launch system of claim 13, wherein the strap includes afirst end including a large ring and a small ring and a second oppositeend including a medium ring, wherein the small ring rests between themedium ring and the large ring when the locking mechanism is in a lockedstate.
 15. The launch system of claim 14, wherein the small ring can fitthough the large ring but not through the medium ring.
 16. The launchsystem of claim 11, wherein the locking mechanism is configured to:apply tension locking the launch collar around the choke point when thetether is tensioned between the launch collar and one or moreground-based attachment points; and release the tension when the tetheris decoupled from the launch collar, the release of the tension causingthe launch collar to fall away from the balloon envelope.
 17. The launchsystem of claim 11, further comprising: a mast on the launch platform,the launch collar being anchored via the tether to a top end of themast, wherein a distance between a top of the mast and underlying groundexceeds a distance between the launch collar and the payload attached tothe lower portion of the balloon envelope.
 18. The launch system ofclaim 11, further comprising: a self-orienting aerodynamic deviceanchored to the launch collar, the self-orienting aerodynamic deviceconfigured to generate a lift force when a cross-wind is present. 19.The launch system of claim 11, wherein the launch platform is anautomobile.
 20. The launch system of claim 11, further comprising: afill port in the balloon envelope, the fill port being located in theupper portion of the balloon envelope at a location above the launchcollar.